<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 表格 -->
    <table>
        <thead>
            <tr>
                <th>姓名</th>
                <th>年龄</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td>小红</td>
                <td>3岁</td>
            </tr>
            <tr>
                <td>小明</td>
                <td>2岁</td>
            </tr>
        </tbody>
    </table>
    <!-- 同一列的行合并rowspan -->
    <table border="1" width="100%">
        <tr>
            <td rowspan="3">一班</td>
            <td>小明</td>
            <td>2岁</td>
        </tr>
        <tr>
            <td>小红</td>
            <td>3岁</td>
        </tr>
        <tr>
            <td>小亮</td>
            <td>4岁</td>
        </tr>
        <tr>
            <td rowspan="3">二班</td>
            <td>张三</td>
            <td>5岁</td>
        </tr>
        <tr>
            <td>李四</td>
            <td>6岁</td>
        </tr>
        <tr>
            <td>王五</td>
            <td>6岁</td>
        </tr>
    </table>
    <!-- 同一行的列合并colspan -->
    <table border="1" width="100%">
        <tr>
            <td align="center" colspan="2">学生列表</td>
        </tr>

        <tr>
            <td>小明</td>
            <td>2岁</td>
        </tr>
        <tr>
            <td>小红</td>
            <td>3岁</td>
        </tr>

    </table>

    <!-- 简单的登录表单 -->
    <form action="">
        <div>
            <label for="username">用户名：</label>
            <input type="text" id="username">
        </div>
        <div>
            <label for="password">密码：</label>
            <input type="password" id="password">
        </div>
        <div>
            <label for="">性别：</label>
            <select name="" id="">
                <option value="men">男</option>
                <option value="woman">女</option>
            </select>

        </div>
        <input type="submit" value="注册">
    </form>
</body>
</html>